I recently bought a DC regulator (power supply and tester.) It is a 15V and 2A power supply with voltage fixed to 1.5V, 3.6V, 4.8V, 6.0V, 7.2V direct output of the sub-grade and the current is adjustable from 0.6 to 2A. It also has potentiometers for fine voltage and coarse voltage, but I do not get any difference when it is connected to a multimeter. I rotated the coarse and fine potentiometers but the output didn't change, not even when I connect it to other electronics.
Is it possible to change the potentiometer from fixed to variable?